Dynamo-electric machine and winding therefor



Sept. 25, 1928. 1,685,737

- G. M. ALBRECHT DYNAMO ELECTRIC MACHINE AND WINDING THEREFOR File J ne 1926 3 Sheets-Sheet 1 I 35 Q2 .34 47 7 4 l 1 2 4 m a I 3 6 lab 2/ E /2 g- Q/vWMAXQ/o DYNAMO ELECTRIC MACHINE AND WINDING THEREFOR Filed June s; 1926 :5 Sheets-Sheet 2 Sept. 25, 1928. 1,685,737 G. M. ALBRECHT DYNAMO ELECTRIC MACHINE AND WINDING THEREFOR Filed June 5, 1926 3 Sheets-Sheet 5 rio'us armature paths Patented Sept. 25,1928.

, UNITEDTSTATESAPATENT OFFICE.

GEORGE M. ALBRECHT, OF MILWAUKEE, WISCONSIN,

0F MILVIAUKEE, WISCONSIN, A

' -MANUFACTURING COMPANY,

DELAWARE.

CORPORATION OF.

DYNAMGELECTRiOMACHINE AND WINDING THEREFOR.

Application filed June 5, 1926. seriai o. 113.904.

This invention relatcsto dynamo-electric machines and windingsltherefor; a i One of tlie objectsis the provision ofa dynamo-electric macl fne in which the inimb r of circuits is-greater than tlie number of poles; and more specifically in cases where the number of pairs. of poles is an odd number. I v j I Another object the provision of machines of the hereinbettorementioned characteristirs in which the nuinbcrfof circuits is equal to the number otpoles multiplied by an even number, andmore specifically, in which said 1111111 061 maybe, for example, 2, 4,8,etc. I, i i @Another. object the provision of machines oi? thehcreinbefore'i'nentioned char acteristics in which the. currents in the vafare equalized. 'Still another obi cct I is the, provision of a winding in fwhichthe potential rise from one'brush to another measured from bar to bar on the commutator will 'be asubstantiallysmooth curve. 1 f I i {i I A further object is to accomplish thehereinbefore mentioned results without. the use of external cross'c'onnectors. I a

Other objects will" ppear hereinafter as the description the invention proceeds. I The novel features of the invent-ion'will appear from this specification and the accompanying drawings forming a part thereof and. disclosing several embodiments the invention, and all these ,novel features are intended to be pointedoutin the claims. 1

Inthc drawingst f Fig. 1 is a diagrammatic view of a dynamo-electric machine embodying the invert tion andntilizlng externalcross connectors.

i Fig. 2 is a diagrammaticview ot a dynamo electrlc mach ne n whichvthe inven tion is cmbodiedin' a modifiedform, no ex ternal cross connectors being utili ed.)

form of lyiiaino electric' machine also embodying the nvention. g

Referring to Fig. 1, the machine here shown has anodd number of pairso'f poles,

tlierc'bcingsixpole's B, C'.' D,.E, F. The armature is here shown of the slotted type, having21 slots. The; commutator has 63 bars to. which are connected 63 l coils here shown of the lap'type. The'number of slots ,gin' tracing through the ,there proceed through coils 1 ,reen-trant winding and'a duplex or,

Fig. 3 a d'agrammatic view of another andbars are thus both odd and. are respectively divisible by the number of pairs of poles. There beingQl slots there are therefore 3 coils per slot. Stated in other words, there are G coil sidesin every slot and as each coil has Qsides it is ordinarily said that the slot contains 3 coils though the coil sides belong to 6 different coils. The winding here shown is what may be termed 'a ASSIG-NOR TO ALLISCHALMERS- doubly reentrant winding of the simplex derstood a winding in which if we be winding at a given commutator bar we must pass through all of the conductors before we again reach the bar at which tracing began. A doubly reentrant simplex wind.

31 and'bar 63. From bar 63 on we may coil 32 to bar 2 and from 2?, 32.4 and soon until. we reach coil 31" which is connected to bar 1 at which tracing began. 2 rounds ot the armature have therefore been made. Such a winding has twice asmany circuits as the number of poles, in this case thereforc,,l2 circuits. It may be noted at trace through this point that a distinction is to be made in general. a multiply in general, a multiplex"winding. In a duplex winiiing the armature has 2 independent simplex windings, that is, if tracing is hegun at a given bar this bar is again reached when halt'of the conductors oi the winding have been traced, it being, then necessary to startat another bar in order to trace the re maining conductors. Such a winding is unsuitable in a machine having an odd number poles for the reason that it cannot be properly equalized.

By properly selecting, the various factors of the machine the win ding such as shown in Fig. 1 may be equalized. The number of slots or bars "must. be an odd number, respectively, divisible by the number of pairsfof poles. Moreover, as is practically always the case in commercial machine when the number of coils per slot is greater than 1 said number must. be prime to the between a doubly or,

ng may be defined as one in which 2 rounds of the armature Under the term simplex is to be un- 1 tracing began coil 11 latter coil being connected to bars 22 and 2 h number of rounds or recntrances of the winding. F or example, whereas in Fig. 1, the number of reentrances is 2 and there is to be more thanone coil per slot the number of coils per slot must be 3 or 5 or 7 and so on. The number of pairs of poles must moreover he odd. The back conductor pitch of the coils of the winding should be odd and for manufacturing reasons is preferably made so that the slot pitch of all coils will be the same. In the particular instance shown the back conductor pitch is 17 and the slot pitch of the coils is 3, it being noted that there are 3% slots per pole. The front conductor pitch of the coils should be made equal to the difference between the back conductor pitch and 2 times the desired number of reentrances of the winding, and is therefore in the present instance equal to 13. The number of circuits desired naturally determines, with a given number of poles, the number of reentrances. That is, referring to Fig. 1 if 12 circuits are desired on a six pole machine the winding is made doubly reentrant. The commutator pitch of the coils is made equal to the number of reentrances, that is, 2, in Fig. 1.

With the factors chosen as hereinbeforc stated the winding may be effectively cross connected It will be noted if we take, for example, coil 1 connected to bars 1 and 3, that this coil is disposed in the same position with respect to poles A and B as is with respect to poles C and D, the

Bars 1 and 22 are therefore equipotential and may be connected with a cross connector here diagrammatically indicated as a conductor It will be noted, however, that coil 11 is in one round of the winding whereas coil 1 is in another round. Equalt zation therefore occurs as between these two rounds. In like manner coil 1 connected to bars 2 and 4 is disposed in exactly the same position with respect to poles A and B is coil 12 connected to bars 23 and 25. Bars 2 and 23 may therefore be connected by a cross connector 34. Coil 1 is in the same round as coil 11 whereas coil'l2 is in the same round as coil 1. It will be apparent therefore that all points of equipotential may be cross connected as shown in Fig. 1. The manner of winding and the choice of factors hereinbefore set forth thus results in a winding which may be effectively equalized inasmuch as coils in different rounds of the winding are disposed at equipotential points, so that there is no possibility that one of the rounds orany of the circuits will tend to carry more current than another, It is obvious that it is immaterial whether these connections are made at the commutator end of the machine or at the other end.

Referring now to Fig. 2 the machine here shown has 6 poles A, B, O, D, E, F. For

the sake of simplicity a comparatively small number of coils per slot has been shown, there being 33 slots and 33 commutator bars. The winding here shown comprises 132 con doctors disposed in the slots, 66 of these conductors being connected in the form of a lap type winding and the remaining (36 in the form of a wave type winding. The lap type winding, in order to distinguish it from the wave type winding, is here shown in heavy lines and the conductors thereof are here shown in'the second and third positions in the slots counting from the outer periphery, although they might be otherwise disposed. It will therefore be apparent that each winding has 33 coils. Each winding has one coil per slot, but if more coils per slot are desired the number must be prime to the number of reentrances of the lap winding. 7

The factors of lap type winding are selected as already set forth with res ect to Fig. 1, and by way of example the winding of Fig. 2 is here shown as also of the doubly reentrant'simplex type inasmuch as if we begin tracingat bar 1, for exai'nple, we pass successfully through coils L L-, L and so on, until we reach coil L which is connected to bar 33. From there we pass through coil L to bar 2 and begin another round of the armature before we again reach bar 1. The lap type winding therefore has 12 circuits. The coil pitches are governed in the same manner as already stated in connection with Fig. 1.

The wave type winding in Fig. 2 comprises three independent wave windings and it is therefore of the triplex type. One of these windings is distinguished by the dotted lines, another by the dot and dash lines and another by the light full lines. The factors for this triplex wave type winding are so chosen that the total number of circuits will be the same as for the lap type winding, that is, 12. Each of thesimplex wave type windings constituting the triplex winding is doubly reentrant and therefore each has 1 circuits so that the 3 simplex windings together constituting the triplex winding have 12 circuits. The average conductor pitch of the wave coils is so chosen that it is equal to the difference between the conductors allotted to the wave type winding and the numberof circuits in the lap type winding, divided by the number of poles. So choosing the average pitch also predetermines the number of circuits in the wave winding as a whole whether the winding be multiplex, multiply reentrant, or any combination; The slot pitch of the wave coils is preferably made the same as for the lap coils if the number of slots per pole is an integer and the slot pitch of the lap coils is equal to the pole pitch and if not then it is made so that the slot pitch of the wave coilsis eqnalto the difference between nectors'may be seen by v t p sideration. It will be noted that vcoils L entrances of thelap type winding, and

the slots per pair of poles and the slot pitchof the lap coils. Inthecase of Fig. 2the slot pitch of the lap coils is 6 while that of the-wave coils is5. The commutator pitch of the wave coils is made equalto the dinerence between the commutator bars per pair of polesand he number of rounds or retherefore 9. 1 I r a o The manner in which the winding'of Fig. 2 is-equalized withoutjthe use ofcross conand L?constituting aygroup, of consecutive coils in a given roundof the lap winding, the terminals of which group are at bars 1 and 7 are balanced; byia group of three wave coils na'mely, acoila in the dot and number of slots, namely,

dash wave windingconnected to barl and bar25, a coil a connectedefrom there to bar 16 and a coil 0 connected from there to bar 7. The last three mentioned coils arein-v 4 fluencedby all of the pairs of poles whereas the lap coils L L L are influenced by only one pair of poles. These 2"groups of coils generate the same electromotive force and are balanced against each other. By

' 1 inspection it will be noted that all of the lap wave coils, group coils are balanced against illustrated. It

by group, as hereinbefore will alsobe inotedthat a coil such as b,

in the dotted wave winding which is con-, nected between bars 3 and ,12 serves as a portion, of an equalizing connection between bars 1 and 12. The lap coil L. "connected 2 to bars 1 and 3 serves as the other portion ofthe equalizing connection between bars 1 and 12 whichare equipotential bars. The

coils L and b are disposedtofv generate equal and opposite ele'ctromotive forces and under normsil'conditions no equalizing current flows through these coils. In a similar manner takingfor example a coil 0 of. the light full line wave winding, which connected to'bars 13 and 23 this serves as a portion of an equalizing connection between the bars 14 and 25, the lap coil L serving as the'other portion. Thewave coil 0 thus serves also to connect the lapqcoilL tothe lapfcoil L these coilsbeing in difierent roundsfo the lap windingu l The same is true with res spect to -wave coil bl asfto coils" L IandL It' will be clear that all of the wave and lap coils serve as portions of equalizing connections. i T '.Fig.- 3 shows how the invention may be applied in securing a 24 circuit equalized lap winding on a; machine having 6 poles A, B, C, D. Fn-F. The armature has'an odd number of 7 commutator bars 2 In the .slots are disposed 156 conductors, 7 f which are connected to form asimplex quadruply reentrant lap winding. The remaining half connected a group of wave coils in the following connoted.

planation 39 and the same has 24 circuits, the same as the lap. winding,

The number of coils p'er'slot' is governed 1n the manner already stated in connection with Figs; 1 and 2. i s

I Takin a given group of consecutive lap coils suc as L, L? and L the'terminals of which group are connected to bars 1 and '13 it will be noted that tothese bars are also the light 'the coils full line wave winding; namely,

a, a and this group of wave coils being influenced by all of the poles whereas the group of lap coils is influenced by'one pair of poles. Moreover the coilai is connected to bar 1 to whichis also connected coil L which coil is'in the 4th reentrance or round of the lap winding if we'begin the first round with coil L The coil m is also'con nected to bar 31' to which is connected coil L in the 3rd round which coil is disposed similarly to coil L and therefore generates the-same electromotive force. To bar 31 is also connected coil L whichis inthe 3rdfrou'nd. Coil a) is connectedto bar 31 and to bar '22 to which latter is connected'coilL in the 2nd round and which coil is located similar to coil L Coil fw" is connected to bars 22 and '13; To bar 22 is also connectedcoil and located similarly to coil being connected to;

coil L the latter bar13 as already Taking'one other insta nce,'it will be noted. that the lap coils L L and D which are inthe- 2nd round if we begin with coil L1 as in the 1st round, arebalanced by a group of wave coils b, b and b in the dot-an'd dash wave'winding. Coil 'b connects between bars 2 and 32 to which latter are connected coils L and L both'in the 4th round, coil L3 being located similarly to'coil L Coil b is connected between bars 32 and bar 23 to whichlatter are co nnected coilsL and L lfbothin the3rd round, coil L being located similarly to coil L Coil b is connectedbetween bars 23, and bar 1a to which latter are connected f lcjoils L and L both in the 2nd round,

coil L being located similar l to'coil L :It will be apparent'without further exi that the lap and wave type wind ings in Fig. 3 are thoroughly balanced and interconnected; I x y It should be understood that the invention claimed is not limited to the exact details of construction shown and described, for obvious modifications may occur to persons skilled in the art.

It is claimed and Letters Patent desired to secure by 11A mult polar dynamo-electric machine having an odd number ofpairsof poles, an

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L in the 2ndround armature comprising a predetermined number of coils connected to form a simplex winding said winding being multiply reentra nt an even number of times and having points of equal otential in different reentrances thereoii: and a predetermined number of equalizing connectionsbetween points of equal potential.

2. A multipolar dynamo-electric machine having an odd number of pairs of poles, an armature for said machine and a winding therefor having a number of circuits equal to the number of poles multiplied by an, even number, and means including a predetermined number of load-current-carrying conductors for equalizing the currents in said Circuits. q

3. A multipolar dynamo-electric machine hving an odd number of pairs of poles, an armature comprising a predetermined number of coils connected to form a simplex winding, said winding. being multiply reentrant an-even number of times and having points of equal potential in different reentrances thereof, and a predetermined number of equalizing connections including a pre determined number of load-current-carrying conductors between points of equal potential.

4. In an armature for a multipolar dynamo-electric machine having an odd number of pair of poles, a winding forsaid armature having a number'of circuits equal to the number of poles multiplied by an even number and having an-odd number of coils the number of said coils being divisible by the number of pairs of poles, and equalizing connections for said windin 5. In a commutator type slotted armature for a multipolar dynamo-electric machine having an odd number of pairs of poles, said armature having an odd number of slots, and an odd number of bars, the number of slots and bars being divisible respectively by the number of pairs of poles, a winding disposed in said slots and connected to said commutator, said winding having a number of circuits equal to the number of poles multiplied by an even number, and a predetermined number of equalizing connections for said winding. 1

6. In a commutator type slotted armature for a multipolar dynamo-e1ectric machine having an odd number of pairs of poles, said armature having an odd number of slots, and an odd number of bars, the number of slots and bars being divisible respectively by the number of pairs of poles, a simplex multiply reent-rantwinding disposed in said slots and connected to said commutator, and a predetermined number of equalizing connections for said winding.

7. In a commutator type slotted armature for a. multipolar dynamo-electric machine having an odd number of pairs of poles, said armature having a number of slots and bars 8. In a commutator type slotted armature for a multipolar dynamo-electric machine having 'an odd number of pans of poles, said armature having a number of slots and bars respectively not divisible by a predetermined multiple of four, thenumber of slots and bars being divisible respectively by the number of pairs of poles, a simplex multiply reentrant winding disposed in said slots and connected to said commutator, and a predetermined number of equalizing connections for said winding.

9. A winding for a multipolar dynamoelcctric machine, including a multiply reentrant lap type winding, and a wave type winding interconnected with said lap type winding.

10. A commutator type armature winding for a multipolar dynamo-electric machine including a multiply reentrant lap type winding, and a wave type winding interconnected with said lap type winding, both windings being connected to the same commutator. i w

11. A winding for a mult-ipolar dynamoelectric machine,

including a multiply 1eentrant lap type winding, and a predetermined number of wave type windings interconnected with said lap winding, the number of said wave windings being such and the individual reentrances such that the total number of circuits in said predetermined number of wave windings isequal t0 the total number of circuits in said lap winding.

12. A winding for a multipolar dynamoelectric machine including a multiply reentrant lap type winding, and afmultiplex Wave type w nding interconnected with said lap winding.

p 13.. A winding for a multipolar dynamoelcctric machine including a multiply rcentrant lap type winding, and amultiplex wave type windinginterconnected with said lap winding, each component of said wave winding being multiply rcentrant.

14:. A winding for a multipolar dynamoelectric machine having an odd number of pairs of poles, including a lap type winding reentrant an even number of times. and a wave type winding interconnected with said lap winding.

15. In a slotted type armature for a multipolar dynamo-electric machine having an odd number of pairs of poles, sait armature having an odd number of slots, the number circuits equal to the nam'o-electric machine,- a winding of slots being divisible by the number. of pairs of poles, a multiply reentra'nt winding disposed in said slots having a number of circuits equal to plied by an even number, and means for electrically equalizing said circuits.

16. In a slotted type armature for a multipolar dymimo-electric machine having an odd number of pairs of poles, said armature having aniodd number of slots, the number of slots being divisible by the number of pairs of poles a multiply rcentrant winding disposed in said slots having a number of number of poles multiplied by an even number, the coils of: said winding per slot being in number prime to the number of reentranccs. and means for electrically equalizing said circ iiits. v p

17. An armature for amultipolar dynamoelectric machine, a Winding for said arma ture including a multiply reentrant lap type winding, and a predetermined number of Wave type windings, the coils of saidwave winding having an average front and back conductor pitch equal to the difference between the number of conductors in said wave winding and the number of circuits in said multiply rcentrant lap winding divided by the number ofpoles.

18. An armature for a multipolar dyfor said armature including a multiply reentrant lap type winding, and a predetermined number of wave type windings, the coils of said wave winding having a commutator pitch the number of poles multithrough connected equal to the difference between the number of bars per pair of poles and the number of reentrances of said lap Winding.

19. An armature for a multipolar dynamoelectrie machine, a Winding-for said armature including a multiply winding, and a predetermined number of wave type windings, the coils of said wave winding having a slot pitch equal to the difference between the number of slots per pair of poles and the slot pitch of the lap coils.

20. A multipolar dynamo-electric machine having an odd number of pairs of poles, an armature for said machine, a commutator having commutating zones equal in number to the number of poles, a winding for said armature having a number of circuits equal to the number of poles multiplied by an even number, said Winding providing an even number of paths independently traceable coils from a zone of one sign to a'zone of opposite sign, the coils comprising said paths being disposed on said armature and connected to said commutator so that a coil in one of said paths is disposed with respect to a given pair of poles similarly to a coil in a clifii'erent one of said paths influenced by a difierent pair of poles and a predetermined number of equalizing connections between pairs of coils disposed as stated.

In testimony whereof the signature of the inventor is affixed hereto.

GEORGE M. ALBRECHT.

reentrant lap type 

